Chemoenzymatic approach to optically active 4-hydroxy-5-alkylcyclopent-2-en-1-one derivatives: an application of a combined circular dichroism spectroscopy and DFT calculations to assignment of absolute configuration.

abstract：:The impact of crystalline forces on the solid-state circular dichroism (CD) spectrum of hypothemycin (), a biologically active molecule extracted from natural sources, has been analyzed by means of time-dependent density functional theory CD calculations. Input structures were extracted from the X-ray geometry of and ...

journal_title：Chirality

authors： Pescitelli G

更新日期：2012-09-01 00:00:00

abstract：:Studies on the interactions between L-O- phosphoserine, as one of the simplest fragments of membrane components, and the Cinchona alkaloid cinchonine, in the crystalline state were performed. Cinchoninium L-O-phosposerine salt dihydrate (PhSerCin) crystallizes in a monoclinic crystal system, space group P2(1), with un...

journal_title：Chirality

authors： Wesełucha-Birczyńska A,Oleksyn BJ,Watroba J

更新日期：2010-06-01 00:00:00

abstract：:The present work firstly described the enantioseparation and determination of flumequine enantiomers in milk, yogurt, chicken, beef, egg, and honey samples by chiral liquid chromatography-tandem mass spectrometry. The enantioseparation was performed under reversed-phase conditions on a Chiralpak IC column at 20°C. The...

journal_title：Chirality

authors： Li S,Liu B,Xue M,Yu J,Guo X

更新日期：2019-11-01 00:00:00

abstract：:Efficient synthesis of several new atropisomeric amino alcohols having 1-phenyl-1H-pyrrole skeleton are reported. Steric arrangements of the products were confirmed by a single-crystal X-ray measurement. The consequences of the size of the N-substituents on enantioinduction were examined by employing the enantioselect...

journal_title：Chirality

authors： Faigl F,Deák S,Erdélyi Z,Holczbauer T,Czugler M,Nyerges M,Mátravölgyi B

更新日期：2015-03-01 00:00:00

abstract：:We introduce a method to detect the activity of ion channels and pores with circular dichroism (CD) spectroscopy. G-quartets obtained by potassium templated self-assembly of 5'-guanosine monophosphate (GMP) are used as CD probes, the bee-toxin melittin as representative pore and gramicidin A as representative ion chan...

journal_title：Chirality

authors： Hennig A,Matile S

更新日期：2008-09-01 00:00:00

abstract：:The effects of temperature on the chiral recognition of cyclic β-amino acid enantiomers on zwitterionic [Chiralpak ZWIX(+) and ZWIX(-)] chiral stationary phases were investigated. Experiments were performed at different mobile phase compositions and under 10°C column temperature increments in the temperature range 10-...

journal_title：Chirality

authors： Ilisz I,Pataj Z,Gecse Z,Szakonyi Z,Fülöp F,Lindner W,Péter A

更新日期：2014-08-01 00:00:00

abstract：:Chirality of amyloid fibrils-linear beta-sheet-rich aggregates of misfolded protein chains-often manifests in morphological traits such as helical twist visible in atomic force microscopy and in chiroptical properties accessible to vibrational circular dichroism (VCD). According to recent studies the relationship betw...

journal_title：Chirality

authors： Dzwolak W

更新日期：2014-09-01 00:00:00

abstract：:The improvement of the biocatalytic reduction of 2-allyl-carboethoxy-cyclopentanone (2) to the corresponding cyclopentanol derivative (+)-(1R,2R)-(1) was accomplished employing baker's yeast in organic media. This chiral cyclopentanol derivative (1), analyzed by high resolution gas chromatography performed over beta-c...

journal_title：Chirality

authors： Fraga CA,Barreiro EJ,da Silva EF,dos Santos AR,KV Ramos MdaC,de Aquino Neto FR

更新日期：1997-01-01 00:00:00

abstract：:We report the preparative separation of rac-zopiclone using malic acid as the resolving agent. Furthermore, two different methods for the analytical determination of zopiclone enantiomers by HPLC on chiral stationary phases are described. The benzodiazepine receptor binding of the isolated enantiomers was investigated...

journal_title：Chirality

authors： Blaschke G,Hempel G,Müller WE

更新日期：1993-01-01 00:00:00

abstract：:Novel chiral diisopropyl spiro bis(isoxazoline) ligands, anti-i-Pr-SPRIX and syn-i-Pr-SPRIX, were designed and synthesized. Their catalytic utility, X-ray crystallographic analyses, and complexation studies demonstrated the structural features of tetraisopropyl spiro bis(isoxazoline) ligand, i-Pr-SPRIX, which is a pro...

journal_title：Chirality

authors： Takenaka K,Lin X,Takizawa S,Sasai H

更新日期：2015-08-01 00:00:00

abstract：:The opening of ortho-substituted phenyl oxiranes by borohydrides is described both in aqueous and solid phases. Some remarkable differences in the regioselectivity and inversion of enantioselectivity of oxirane ring-opening are reported. The results obtained are compared with previous studies and have allowed some fac...

journal_title：Chirality

authors： Doussot J,Guy A,Siaugue JM,Ferroud C,Guieres AF

更新日期：1999-01-01 00:00:00

abstract：:The stability of Chiralpak AD chiral stationary phase under various solvent conditions was investigated. An analytical method for the detection of the presence of solubilized Chiralpak AD coating was developed using CD spectroscopy (CD signal at 245 nm). In addition, NMR analysis of the solubilized polymer revealed a ...

journal_title：Chirality

authors： Welch CJ,Fairchild J,Sajonz P

更新日期：2007-08-01 00:00:00

abstract：:8-Prenylnaringenin (8PN) is a naturally occurring bioactive chiral prenylflavonoid found most commonly in the female flowers of hops (Humulus lupulus L.). A stereospecific method of analysis for 8PN in biological fluids is necessary to study the pharmacokinetic disposition of each enantiomer. A novel and simple liquid...

journal_title：Chirality

authors： Martinez SE,Lakowski TM,Davies NM

更新日期：2014-08-01 00:00:00

abstract：:The chiral squaramide catalysts (8-15) were synthesized, and their catalytic efficiency in the enantioselective conjugate addition of pyrazolones to nitroalkenes was described. This protocol provides excellent chemical yields (up to 93%) of chiral 5-methyl-4-(2-nitro-1-arylethyl)pyrazol-3-ol derivatives with high enan...

journal_title：Chirality

authors： Aydin AE,Culha S

更新日期：2021-01-11 00:00:00

abstract：:The optical rotation sign/absolute configuration relationships of several alpha-methyl-alpha-arylglycines have been reinvestigated by crystallographic methods, as they have been found to be inconsistent in recent literature. Assignments previously made by enzymatic resolution, by analogy with natural tertiary aminoaci...

journal_title：Chirality

authors： Ferron L,Guillen F,Coste S,Coquerel G,Plaquevent JC

更新日期：2006-08-01 00:00:00

abstract：:Compared to simulated moving bed (SMB) chromatography, fractional crystallization is a simple and economical method for enantioseparation. Therefore, the coupling of SMB chromatography and fractional crystallization is suggested for enantioseparation of racemic compounds. In this work, a nonsteroidal antiinflammatory ...

journal_title：Chirality

authors： Hong Lu Y,Bun Ching C

更新日期：2004-10-01 00:00:00

abstract：:Despite that a number of experimental and theoretical investigations have been carried out to determine the structure of trialanine in water, the reported populations of polyproline II (PPII) and β-strand conformers vary and were found to be dependent on which spectroscopic method was used. Such discrepancies are due ...

journal_title：Chirality

authors： Oh KI,Lee KK,Park EK,Yoo DG,Hwang GS,Cho M

更新日期：2010-01-01 00:00:00

abstract：:A Micelle-enhanced ultrafiltration (MEUF) separation process was investigated that can potentially be used for large-scale enantioseparations. Copper(II)-amino acid derivatives dissolved in nonionic surfactant micelles were used as chiral selectors for the separation of dilute racemic amino acids solutions. For the al...

journal_title：Chirality

authors： De Bruin TJ,Marcelis AT,Zuilhof H,Rodenburg LM,Niederländer HA,Koudijs A,Overdevest PE,Van der Padt A,Sudhölter EJ

更新日期：2000-08-01 00:00:00

abstract：:This article describes a very useful extension of an unique column switching technique called "Simulated Moving Columns" (SMC) that was previously reported for chiral high performance liquid chromatography (HPLC) (Zhang and McConnell, Journal of Chromatography A 2004;1028:227-238). SMC uses two or three short chiral c...

journal_title：Chirality

authors： Zhang Y,Dai J,Wang-Iverson DB,Tymiak AA

更新日期：2007-09-01 00:00:00

abstract：:The five-steps synthesis of a hemicryptophane cage combining a benzene-1,3,5-tricarboxamide unit and a cyclotriveratrylene (CTV) moiety is described. Chiral high-performance liquid chromatography (HPLC) was used to resolve the racemic mixture. The absolute configuration of the isolated enantiomers was assigned by comp...

journal_title：Chirality

authors： Long A,Jean M,Albalat M,Vanthuyne N,Giorgi M,Górecki M,Dutasta JP,Martinez A

更新日期：2019-11-01 00:00:00

abstract：:A rapid and simple procedure for enantioselective preparation of 2- and 3-substituted 2,3-dihydro[1,4]dioxino[2,3-b]pyridine derivatives (A and B, respectively) is described. The enantiomeric purity of each isomer was determined by capillary electrophoresis using a dual-cyclodextrin system (S-beta-CD/beta-CD) dissolve...

journal_title：Chirality

authors： Lazar S,Soukri M,El Haddad M,Akssira M,Leger JM,Jarry C,Morin P,Guillaumet G

更新日期：2005-01-01 00:00:00

abstract：:Resolution of mandelic acid with (-)-(1R,2S)-ephedrine in water and ethanol produces intermediate diastereomeric salts with greatly disparate solubilities and melting points. Single crystal X-ray analysis of the less (L) and more (M) soluble (-)-ephedrinium mandelates (I, II) shows crystal structures which are isoster...

journal_title：Chirality

authors： Valente EJ,Zubkowski J,Eggleston DS

更新日期：1992-01-01 00:00:00

abstract：:The stereochemistry of tolperisone, a chiral aryl-alkyl basic ketone was investigated by means of circular dichroism (CD) and ultraviolet (UV) spectroscopy. The unusually high optical activity of tolperisone hydrochloride in the n-->pi* region is interpreted by the presence of a chiral conformer in solution. For stere...

journal_title：Chirality

authors： Zsila F,Hollósi M,Gergely A

更新日期：2000-11-01 00:00:00

abstract：:Weinreb amide 3 was synthesized using isobutyl chloroformate, carbonyldiimidazole, or ethylcarbodiimide as the coupling agent in the reaction of Boc-phenylalanine with O,N-dimethylhydroxylamine hydrochloride. An optically active oil was isolated along with an optically inactive solid irrespective of the type of coupli...

journal_title：Chirality

authors： Zheng X,Donkor IO,Miller DD,Ross CR 2nd

更新日期：2000-01-01 00:00:00

abstract：:The chiral discrimination ability of two recently prepared chiral stationary phases (CSP 1 and CSP 2), based on a leucine derived chiral selector, was tested for the enantiomers of dihydropyrimidone (DHPM) derivatives and compared with the commercially available Hyun-leucine CSP 3 and classical Pirkle-leucine CSP 4. B...

journal_title：Chirality

authors： Forjan DM,Gazić I,Vinković V

更新日期：2007-06-01 00:00:00

abstract：:Supercritical fluid chromatography (SFC) is already used for enantioseparation in the pharmaceutical industry, but it is rarely used for the separation of chiral pesticides. Comparing with high performence liquid chromatography, SFC uses much more environmnetal friendly and economic mobile phase, supercritical CO2 . I...

journal_title：Chirality

authors： Zhao L,Xie J,Guo F,Liu K

更新日期：2018-05-01 00:00:00

abstract：:Ropivacaine hydrochloride monohydrate (ropivacaine) is a new local anaesthetic agent which is administered exclusively as the (-)-(S)-form. The aim of the study was to determine whether metabolic racemisation of (-)-(S)-ropivacaine occurs. This was tested in man, rat, dog, and sheep after different routes of administr...

journal_title：Chirality

authors： Arvidsson T,Bruce HF,Halldin MM

更新日期：1995-01-01 00:00:00

abstract：:The R enantiomers of some of the 2-arylpropionic acid non-steroidal antiinflammatory drugs (NSAIDs) are known to undergo metabolic chiral inversion to their more pharmacologically active antipodes. This process is drug and species dependent and usually unidirectional. The S to R chiral inversion, on the other hand, is...

journal_title：Chirality

authors： Jamali F,Lovlin R,Aberg G

更新日期：1997-01-01 00:00:00

abstract：:Fluoroquinolones are popular class of antibiotics with distinct chemical functionality. Most of them are ampholytes with one chiral center. Stereogeneic center is located either in the side ring of Gatifloxacin (GFLX) or in the quinolone core of Ofloxacin (OFLX). These two amphoteric fluoroquinolones have terminal ami...

journal_title：Chirality

authors： Hassan RM,Yehia AM,Saleh OA,El-Azzouny AA,Aboul-Enein HY

更新日期：2018-06-01 00:00:00

abstract：:The simultaneous disposition of fenoprofen enantiomers in synovial fluid and plasma was studied in 11 patients with arthritis and chronic knee effusions treated with a single oral dose of 600 mg rac-fenoprofen. A plasma sample and a synovial fluid sample were collected simultaneously from each patient up to 16 h after...

journal_title：Chirality

authors： De Miranda Silva C,Marques MP,Barissa GR,Donadi EA,Da Silva LM,Lanchote VL

更新日期：2007-05-05 00:00:00